"Rotting" patches on Phalaenopsis

[fattytuna]

As you can see, brown, mushy patches are appearing on my leaves.

Its winter right now, night temperatures around 12C. I water whenever the sphagnum on top feels dryish. its on a east facing window and only receives indirect sunlight.

Previously I watered once a week, perhaps its a combination of being too wet and cold?

Thanks in advance.

[King_of_orchid_growing:)]

Remove infected portions of the leaves promptly with a sterilized pair of cutters or a sterile razor blade.

Too wet, too cold encourages this disease to spread like wildfire.

Treat immediately.

It is bacterial infection in nature.

[fattytuna]

Thanks for your reply

[lepetitmartien]

There seems to be a larger zone round the clearly brown one, if it's not dust wiped (that's the effetc on the picture), the affected zone is larger. Cut outside of it.

- Use a sterilized tool to cut large (about an 2-2,5cm out of the zone)
- Spray a bactericide (a copper based will do, phals do well with them) on it after, and on all the friends around, this thing spreads
- you can put cinnamon powder on the cut

12°C is very low, phals like it hotter. It should be at 16-17° at the very least.

[silken]

I would like to add, that the top of the moss will dry out first and you should check how wet the interior of the pot is before watering. It should be dry or very close to it at the bottom and centre before watering. I suspect you are over-watering which can lead to root rot. In that cold of temps the cold and wet will equal rot of some sort. And I agree, Phals prefer to be in a warmer place than that.

[RosieC]

Watering based on moss on the top is likely to mean its not dry lower down and you overwater. Also it sounds too cold to me. It might cope over winter like that if dry, but needs warmer to grow, and combined with being wet will cause problems (I've killed Phals that way, its easy to do if you don't realise).

[james mickelso]

It doesn't look like the roots are rotting just yet but that isn't far off if you are already facing rot in the leaves. I would curtail the watering quite a bit if you ca't provid a warmer enviromen. Something like 60f would beas low as I would get. But a dry media anddry-ish root environment will keep the pesky root rot at bay. Phals can take a short dry spell especially if it is cold.

[silken]

The air roots look fine but I am worried about the ones in the pot, which we can't see!